Archaeology

Amazon Garden City

The world’s favourite rainforest once had towns in it

RAINFORESTS are often thought of as virgin habitats: in other words, pristine ecosystems unaltered by the hand of man. A moment's thought shows that this cannot truly be so. People do live in rainforests, and where people live they must alter things. But the fact that those who live there these days tend to make their living by hunting wild animals and gathering wild plants may suggest that Homo sapiens could, in principle, be just another forest species—a natural part of the ecosystem that alters it only to the extent that any species inhabiting it would. To that extent, the forest is still “virgin”.

In the world's largest rainforest, though, this argument no longer holds. The past few years have brought evidence suggesting that parts of the Amazon forest were settled and farmed before Europeans arrived in the area. Now Michael Heckenberger of the University of Florida, Gainesville, and his colleagues have provided some more. In a paper published in this week's Science they look at part of Brazilian Amazonia called the Upper Xingu. Here, they found, humans flourished between about 1,500 years ago and 400 years ago. Moreover, these people lived in urban societies that, even if they did not resemble traditional cities, matched them in population and social organisation.

Dr Heckenberger and his colleagues examined 28 settlements in Upper Xingu. At first blush, each settlement could have passed for an independent town or village, but closer examination suggested they were actually organised into two groups that the archaeologists refer to somewhat grandly as “galactic clusters”.

Each cluster had a central settlement, two large daughters 3-5km (2-3 miles) away to the north-west and south-east, and two smaller daughters 8-10km away to the north-east and south-west. All of these settlements, mother and daughters, were fortified with palisade walls and ditches, and contained streets aligned north-west—south-east, north-south and north-east—south-west. These streets linked up with cross-country roads that ran through the farmed area around a settlement to other centres of population within the cluster, including smaller settlements still, which were unfortified.

The most characteristic feature of each settlement, regardless of its size, was a plaza—an open space that acted as a cemetery and may have been a marketplace. It was also, the archaeologists suspect, a place of political assembly, just as the agora in an ancient Greek city was both marketplace and legislature.

Dr Heckenberger and his colleagues interpret all this as what might, in modern parlance, be thought of as a city surrounded by a set of isolated suburbs, a bit like the satellite garden cities that were popular in European town planning during the first half of the 20th century. Each cluster, they reckon, would have had a population of more than 2,500 people. Until a few centuries ago in a place like Europe, that would have constituted a sizeable town.

Indeed, a more general survey of the Upper Xingu suggests these cluster settlements were the norm. The team reckon there were 15 such clusters around, occupying an area of 20,000 square kilometres (8,000 square miles) and with a combined population of over 50,000. A flourishing settled area, then, and certainly no virgin forest.

Moreover, Dr Heckenberger sees similarities between his team's discoveries in Brazil and others from eastern North America and parts of Europe. There, too, early urban settlements may have been larger than appears at first sight.

All this argues that, for reasons of the history of their own subject, archaeologists are too fixated on the idea of big urban centres such as those that developed along the great rivers of Egypt, Mesopotamia and northern India. Such places are spectacular but not, perhaps, typical. A less showy system is better suited to settling a forest. The suburbs, it seems, are not a new invention after all.